Air conditioning apparatus



Nov. 5, 1940. w. SHURTLEFF AIR CONDITIONING APPARATUS 2 Sheets-Sheet 1Filed Jan. 12. 1938 llllvl WILFRED \SHURTLEFF AU 4 M a 5 A3 a 4 a m a W65 3 5 2 PW Z 6 O 3 ad I 4 Nov. 5, 1940. w. SHURTLEFF AIR CONDITIONINGAPPARATUS 2 Sheets-Sheet 2 Filed Jan. 12, 1938 \illllllllllllkl WILFREDSHURTLEFF- Patented Nov. 5, 1940- umrao STATES- PATENT OFFICE- AIR.CONDITIONING APPARATUS Wilfred Shul'tlefl, Moline, 111., assignor a TheHerman Nelson Corporation, Moline, lit, a corporation of IllinoisApplication January 12, 1938, Serial No. 184,519

I 13 Claims. v(c1. 98-38) exchange element.

A further object of the invention is to provide air conditioningapparatus having an inlet for outdoor air and an inlet for room air,wherein 15 the outdoor air is prevented in a novel manner from passingdirectly into the room through the room air inlet.

Another object of the invention is to provide air conditioning apparatuswherein inlet air is divided into. distinct currents, and, where theinlet air is from different sources, these currents have intersectingpaths of movement to insure a thorough mixing thereof.

n A still further object of the invention is to provide air conditioningapparatus, wherein air taken from outside the room will be caused tomove in one direction when being mixed with air taken from inside theroom, and in another shorter direction of less resistance through theapparatus, when all of the air is being taken from the outside.

A still further object is to provide an air conditioning apparatusimproved damper control M for variably proportioning the amounts ofinlet air taken from different sources to meet different conditions ofoperation.

Other objects and features of the invention will more fully appear fromthe following detailed description taken in connection with theaccompanying drawings which illustrate a single embodiment thereof, andin which:

-Figure 1 is a view in elevation o1 air conditioning apparatus embodyingthe features of the present invention, the forward wall of the casingbeing removed to show the cooperative relationship of theinstrumentalities therein:

Figure 2 is a vertical section through the apparatus showing thecooperative relationship of the inlet dampers, when all the air is beingtaken from outdoors, taken substantially on line 1-11 of Figure 1;

Figure 3 is an enlarged fragmentary sectional view taken through theinlet air mixing compartment to show the cooperative relationship of thedampers when all the inlet air is being taken from indoors; and

Figure 4 is a similar view showing the dampers set for admission ofinlet air both from in-' doors and outdoors, the; outdoor damper beingset to admit a predetermined minimum amount of air.

As shown on the drawings:

As illustrative of my present invention, air

conditioning apparatus is disclosed in the drawings which embodies acasing, generally indicated at Hi, this casing being preferablyconstructed of sheet metal and of generally rec-,

tangular configuration.

The interior of the casing is separated by' means of partition members Hand I2 to provide end compartments l3 and I4 which are, separatedlongitudinally of the apparatus by means of a central or intermediate,compartment I5.

Vertically, the intermediate compartment I5 is separated into an uppercompartment l6 and a lowercompartmentl'l by heat exchange apparatus I8.

The lower compartment ll communicates on its forward side with theinterior of the room in which the apparatus is located through an inletopening i9 provided with a plurality of louvers 20. The inlet openingwiththe louvers therein is preferably located on the 'forward side ofthe casing.

At the rear side, the wall of the casing is provided with'an inletopening 2| which establishes radiator extending entirely across theintermediate compartment l5 so that all inlet air entering the mixingchamber willhave to pass through the heat exchange member beforereaching the upper chamber 16 of the apparatus.

The radiator comprises a plurality. of tubes 25, which are adapted tocarry steam. These I tubes a're'perforated on their under side in orderto permit-expansion of the steam from the tubes into a 'streamlinedsurrounding casing 26 which forms heat exchange surfaces that will beengaged by inlet air passing through the radiator. By means of suitablevalves, the radiator may be throttled to increase and decrease itsheating effects.

The upper chamber [6 is provided with a plurality of fans 21 which areadapted to draw air a from the lower or mixing compartment I! throughthe heat exchange means or radiator into the upper compartment fromwhich the fans discharge the conditioned air through an outlet 28 at thetop of the casing, this outlet containing a plurality of inclined vanes29 for controlling the direction in which air will be discharged intothe room.

The rotors of the respective fans are mounted on a single shaft 30 whichextends longitudinally of the upper chamber and is rotatably supportedin any suitable manner. This shaft is connected to a driving motor 3|which is mounted in one of the end compartments, in this instancecompartment I4.

Since it is a characteristic of an electric motor to heat up duringoperation, economy of operation ofthe air conditioning apparatus ismaterially increased by mounting the fan motor outside of the air streamwhich is being conditioned.

It is also preferable that the air which is being circulated through theapparatus be filtered, and for this purpose a filter 32 may be mountedin compartment l6 above the heat exchange means. This filter may be ofany desired construction.

Moreover, for controlling the fan discharge, the individual fans areprovided with an adjustable slide gate valve 33 at its outlet opening.

For controlling the admission of room air and outdoor air to the mixingchamber and for assuring that the outdoor and indoor air are properlymixed before being circulated through the heat exchange apparatus andthence into the room, the mixing compartment is provided with an out- 40door air control damper generally indicated at 34 and an indoor aircontrol damper generally indicated at 35.

These dampers are interconnected for operation to give three distinctresults, namely:

(1) During the night, when the room is unoccupied, the indoor air orre-circulation damper 35 is arranged to be held wide open in order toenable aspiration of air heating of the room. Such an arrangement savesfuel and effects heating of 50 the room without the necessity ofoperating the fans.

(2) For the condition where the occupied room is to be heated andventilated with one-third outdoor air and two-thirds or any otherdesired 55 minimum proportion of re-circulated or indoor air. For thiscondition, the outdoor damper is arranged to be mechanically heldone-third open and the re-circulation or inlet room air damper isactuated to two-thirds open position by the 60 suction of the fan. Theinlet room air damper is so constructed as to be free to automaticallyclose at any time a strong wind blows an excess of outdoor air into thelower or mixing chamber.

During such operation, the radiator steam input 65 may be controlledeither manually or by means of thermostatic control in response totemperature changes of the room.

(3) For conditions where the room tends to become overheated either frombodily heat, sun or 70 any source of uncontrolled heat the admission ofoutdoor air is arranged to be controlled by damper 34 either manually orthrough suitable thermostatically operated and controlled mechanism togradually open the outdoor air inlet gravity until the outdoor air inletdamper is wide open to allow full volume of outdoor air to enter themixing chamber. Under such operation it has been found desirable andpreferable to shut off the steam to the radiator before the outdoor airinlet damper is open above the one-third or other minimum setting so asnot to waste fuel.

The inlet air damper comprises a plurality of vanes 36 which aredisposed in parallel relation and are hinged along similar edges asshown at 31 for swinging movement into open and overlapped closedpositions. Simultaneous actuation of the vanes is secured byinterconnecting the vanes by means of a bridge member 38. The damper inits fully open position is arranged to abut a suitable stop member 39.

The vanes and connected mechanism are biased by means of a suitableweight 40 which is disposed on the opposite side of the pivots for thevanes, so that this weight tends to actuate the damper toward closedposition by the action of gravity thereon.

It will be noted that, if desired, the weight 40 may be so disposed inrelation to the vanes that the weight will actuate the damperto fullyclosed position, or the weight may be placed in such position thatinstead of the damper being moved to fully closed position it willassume a partially open position depending upon' the relationship of theweight 40 thereto. However, regardless of whether the damper 35 isarranged to be fully or partially closed by gravity, the damper mayreadily be moved to entirely closed position whenever the flow of airtherethrough is reversed for any reason, such as a strong wind blowingthrough the outdoor inlet of the apparatus. Such an arrangement isadvantageous in that it prevents cold air from blowing out through theroom inlet air opening into the room, whereby undesirable drafts wouldbe set up.

The outdoor air inlet damper 34 comprises an elongated vane 4! which ispivoted as at 42 at its ends on its longitudinal center line forswinging movement.

Swinging movement of the vane 4| is controlled by means of a shaft 43which extends longitudi- 44 which is connected at its free end to oneend of a connecting link 45 having its other end pivotally connected tothe vane 4| at a point laterally displaced from its center of rotation.

With this arrangement, it will be observed that movement of the shaft 43in one direction will actuate the vane or damper 4| toward openposition, whereas movement of the shaft in the opposite direction willmove the damper toward closed position.

The inlet outdoor air entering opening 2| of the casing is conducted ina generally upward direction by means of an upper baflle plate 46 and alower baflle plate 41. The damper is arranged to close the channeldefined by these abutment plates by having its lateral edges abut theinnermost ends of the baflies as at points 43 and 49, in which positionthe vane 4| is disposed at substantially an angle of 45 relative to thefull open position of the vane.

It will be observed that when the edge of the (not vane 4| associatedwith baiiie 4'| is opened a predetermined amount from its closedposition of abutment at point 49 with the baflle, the other edge of thevane is still associated with baflie 46. In other words; for apredetermined open position of the vane 4| inlet air is prevented frompassing over the top edge of the vane by the baflie 46, but is free tomove past the lowermost edge of the Vane. In this position, the enteringair will be forced into a downwardly directional path as shown in Figure4. This direction of entering outdoor air assures that the air will bemixed with air which may be entering through the indoor air inletdamper.

This forced mixing of outdoor and indoor air when a, predeterminedminimum of outdoor air is being admitted with indoor air is ofparticular advantage in air conditioning apparatus having a throttlingtype radiator.

With the usual type of ventilator or air conditioner with the usualdamper arrangements, freezing of the radiator often results because thedampers are so arranged as to permit the passage of cold air through theradiator without being properly mixed with warm air. If the radiator isthrottled down, thereis danger of this cold air, where the outdoortemperature is below freezing, of the radiator becoming frozen in spots.In the novel damper-raised arrangement of my present invention, suchdanger is eliminated by causing the outdoor air to dive downwardly intothe warm air stream from the indoor air inlet, thus causing a thoroughmixing of the cold air with a sumcient amount of warm air to raise theresulting mixture to a temperature above freezing before it passesthrough the radiator. e

Although the baiile 46 in the present instance is arranged to cooperatewith the vane 4| to direct the cold inlet air downwardly at apredetermined minimum open position of the vane of substantiallyone-third its total open position, it will be appreciated that thebattle 46 may be arranged to provide such operation at any desiredpredetermined minimum opening within the limits of the arrangement.

As a practical matter, it has been found that with this method, athorough mixing of onethird cold air with two-thirds re-circulated airwill always insure a final temperature above the freezing point intheair passing through the radiator even down to thirty degrees below zerofor outside weather conditions.

If the room should tend to overheat when outdoor temperatures are from40 to 60 F., it is desirable to automatically gradually increase theamount of outdoor air until a maximum volume is taken from outdoors inorder to cool the room. At these temperatures a large volume of outdoorair wil1-not tend to freeze the radiator so that t is not important toinsure that the-outdoor air be mixed with indoor air before beingdischarged into the room. Under such conditions, the damper 34 may beactuated so that the vane 4| is moved to fully open position as shown inFigure 2. In this position of the vane 4|, it will be observed that theoutdoor air is no longer caused to dive downwardly into the bottom ofthe casing, but is permitted to move in a shorter direct path toward theupper part of the casing. This shorter path has less resistance to themovement of the air than in the case where the cold air is beingprojected downwardly for mixing with any warm air which might beentering through the indoor air inlet.

A lost motion connection is provided between the outdoor air damper 34and the indoor air damper 35. Afflxed to the underside of vane 4| is adownwardly projecting plate 50 which is provided at its lower edge withspaced lugs 5| and 52 between which an elongate link member 53 issupported for swinging movement.

The member 53 is pivotedat one end as shown at 54 to the plate 50, andis pivotally connected at its other end to a link member 55. The otherend of link member 55 is pivotally connected as at 56 to one of thevanes 36 of the indoor air inlet damper.

with the foregoing arrangement, it will be observed that when the vane4| is in fuJly closed position as shown in Figure 3, the lug 5| is inengagement with link member 53 and will force the vanes 36 of the indoorair inlet damper 35 to fully opened position. This adjustment of thedampers is for night operation of the apparatus, at which time it isdesirable to admit full volume of air through the inlet damper 35,whereby the air in the room may aspirate by convection currents throughthe apparatus.

At the fully opened position of vane 4| the lug 52 engages link member53 and forces the vanes of damper 35 into fully closed position, wherebyfull volume of outdoor air may enter the apparatus. This setting of thedampers is utilized where outdoor air is used for cooling an overheatedroom.

Between these extreme closed and open posh/ supply of outdoor air isspecified by law. For

such setting, as shown in Figure 4, the damper 35 is not opened to itswidest extent, but .will be actuated to substantially two-thirds openposition by the flow of circulated air therethrough. Moreover, since thedamper 35 is of the gravity closing type, this damper is free to move toclosing position at any time there is a back draft or the flow of inletair therethrough is reversed.

From the foregoing description, it will be apparent that the hereindescribed invention provides novel air conditioning apparatus whereinoutside air and air from the room in which the apparatus is located maybe thoroughly mixed before passing it through a heat exchange element;apparatus in which outdoor air is prevented in a novel manner frompassing directly into the room through the room air inlet, thus settingup draft in the room; in which inlet different sources to meet difierentoperating conditions.

The invention has been described herein more or less precisely as todetails, yet it. is to be understood that the invention is not to belimited thereby, as changes may be made in the arrangement andproportion of parts, and equivalents may be substituted, withoutdeparting from the spirit and scope of the invention.

I claim as my invention:

1. Air conditioning apparatus comprising a casing, a heat exchangeelement separating the casing into two chambers, one of said chambershaving an outlet opening and the other a plurality of inlet openingsadapted to communicate with difierent air sources, means for circulatingthe air from the latter chamber through the heat exchange element intothe former chamber, dampers respectively associated with said inletopenings, and means connecting said dampers for independent operation atcertain relative positions thereof, and dependent operation at otherrelative positions thereof.

2. Apparatus of the character described comprising a casing defining amixing chamber having a first air inlet and a second air inlet, saidinlets communicating with. difierent air sources, means to discharge airfrom said chamber, interconnected damper means for controlling the inletair arranged to admit partial fiow through said first inlet when air isbeing taken in through the second inlet, and admit full flow throughsaid first inlet when no air is being taken in through the second inlet,and means including the damper associated with the first inlet fordirecting said partial flow of air in its movement to said dischargemeans through a relatively long path in mixing relation with the airentering the second inlet, and through a relatively shorter path whenfull flow is admitted through the first inlet.

3. Apparatus of the character described comprising an air conditioningelement, a casing for said element defining a mixing chamber on theinlet side of said element, said chamber having an inlet for air to bere-circulated and an inlet for outdoor air, means for circulating airfrom the mixing hamber through said element, an outdoor inlet amper,baille means associated with said damper and cooperative therewith todirect a proportioned stream of outdoor air in a direction to form anintimate mixture with re-circulated air before any air from eithersource is circulated through said elements, and means for altering thedirection of outdoor air fiow into a direct flow path of reducedresistance when the outdoor damper is wide open and all the inlet air isfrom outdoors.

4. In apparatus of the character described including a steam radiator ofthe throttling type, a casing for said radiator defining a mixingchamber below said radiator, means for circulating air from the mixingchamber through said radiator, and means including interdependentdampers in said chamber for controlling the admission of inlet airthereto from two sources, one the room in which the casing is locatedand the other outdoors, said means being arranged to deflect outdoor airdownwardly within said chamber and room air upwardly when air entersfrom both sources, and direct the inlet air upwardly when all the airentering the chamber is from one of said sources.

occupied and up to one hundred per cent of outdoor air in order to coolthe room when overheated, and including a steam radiator adapted to bethrottled; a casing for the radiator defining a mixing chamber, meansfor circulating air from. said chamber through the radiator, means insaid chamber for intimately mixing outdoor air and room air of widetemperature diflerences before it is circulated through the. radiator,whereby cold streaks which might freeze the condensate in said radiatorwhen the outdoor air is below freezing are eliminated, said meansincluding a room air damper and an outdoor air damper, the room airdamper being normally automatically responsive to the operation of saidcirculating means at partially open positions of the outside air damper,and a lost motion connection between said dampers for forcing the roomair damper to closed position-when the outdoor air damper is fullyopened.

6. In an air conditioning unit, means for circulating room air throughthe unit, means for controlling the inlet of room air to said unit, saidmeans comprising a damper arranged to normally open and close inresponse to the operation and non-operation of said first means, andmeans for restraining the damper against closing movement when saidfirst means is not in operation.

7. In an air conditioning unit, means for circulating room air throughthe unit, means for controlling the inlet of room air to said unit, saidmeans comprising a gravity closing damper normally maintained open apredetermined amount by the flow of air therethrough when said firstmeans is operating, and means for actuating the damper to a greateropening than said predetermined amount and latching it against closureby gravity.

8. In an air conditioning unit, means for circulating room air throughthe unit, means for controlling the inlet of room air to said unit, saidmeans comprising a damper, means for selectively locking the damper infully open and fully closed positions, said damper between said extremepositions beingfree to open in response to the movement of inlet airtherethrough when said first means is operating, and closed by gravitywhen said first means is stopped.

9. In an air conditioning unit, means for cir-' culating outdoor airthrough the unit, means for controlling the inlet of outdoor air to saidunit, said means comprising a damper vane pivoted intermediate itslateral edges for swinging movement, a baflle associated with one ofsaid lateral edges of said vane operative for a predetermined movementthereof from closed toward open position to force the inlet air to passaround the other lateral edge, but for further opening movement of thevane to enable inlet air to pass around both lateral edges.

10. In an air conditioning unit, means for circulating air through theunit, radiator means in said unit for heating air passing through theunit, means for controlling the inlet of outdoor air to said unit, saidmeans comprising a damper vane pivoted for swinging movement, a bafileassociated with said vane and operative therewith to direot apredetermined minimum volume of the entering outdoor air downwardlyrelative to the radiator, and a maximum volume of the air in an upwarddirection toward the radiator.

11. An air conditioning unit having a pair of air inlet openings,adjustable dampers for proportioning the fiow of inlet air through saidopenings, one of said dampers being free to open in response to flow ofinlet air therethrough. and move toward closing position by gravity asthe flow of air is decreased, the other of said dampers 'beingadjustable to a position wherein a predetermined minimum of air isadmitted, but operable to the extreme positions of fully closed andfully opened positions, and a lost motion connection between saiddampers arranged to force the former damper to fully closed and fullyopened positions when the latter damper is at its extreme positions. I

12. Air conditioning apparatus comprising a casing, a heat exchangeelement separating the casing into two chambers, one of said chambershaving an outlet opening and the other a plurality of inlet openingsadapted; to communicate with difierent airrsources, means forcirculating the airirom the latter chamber through the heat exchangeelement into the former chamber, first and second dampers respectivelyassociated with said inlet openings, and means for dependently actuatingthe first oi said dampers in response to the movement of the seconddamper to certain positions, said latter means including a. lost motionconnection enabling independent actuation of said dampers at certainother positions of said second damper.

13. Air conditioning apparatus comprising a casing, a heat exchangeelement separating the easing into two chambers, one of said chambershaving an outlet opening and the other a plurality of inlet openingsadapted to communicate with difierent air sources, means for circulatingair from the latter chamber through the heat exchange element into. theformer chamber, a first damper and a second damper respectivelyassociated with said inlet openings, said first damper being normallyresponsive to the\oper-ation of said means, and common actuating meansfor said dampers operative to actuate the first damper to full openposition when the second damper is fully closed, and actuate the firstdamper to fully closed position when the second damper is fully opened,said actuating means including a lost motion connection releasing saidfirst damp er for normal operation at intermedialfi posi tions of thesecond damper.

WIIJ'RED SHUR'ILEFF. v

